Frequently Asked Questions

What is the first thing to check when the check engine light comes on?

• Check for obvious issues: a loose or damaged gas cap can trigger the light and is an easy first step.
• Listen and look: unusual noises, loss of power, or smoke signal urgent attention and possible towing.
• Review recent fueling or maintenance — contaminated fuel or a recent service can cause codes to appear.
• If a repair is needed under warranty, repairs must be performed at a certified dealership to retain coverage.
• Nalley Toyota of Roswell often provides lower immediate and long-term costs than independent shops, with factory-trained technicians and OEM parts.

What does it mean when the check engine light comes on in a 2025 Toyota Highlander?

• The light indicates the vehicle’s onboard diagnostics detected a fault — from minor issues to serious engine or emissions problems.
• Codes range from small sensors to engine misfires; a diagnostic scan identifies the specific cause and recommended repair.
• Ignoring codes can increase repair costs and risk further damage; certified dealership service protects warranty coverage.
• At Nalley Toyota of Roswell our diagnostics are performed by factory-trained techs that help drivers save immediately and over the long term.
• We document repairs and follow Toyota procedures so covered warranty work is completed correctly and efficiently.

What is the most common reason for check engine light on a 2025 Toyota Highlander?

• Common causes include oxygen sensor failures, loose gas caps, evaporative emissions leaks, and ignition misfires.
• Fuel trim and O2 sensor codes are frequent and, if unaddressed, can shorten catalyst life and increase fuel costs.
• Quick dealer diagnostics pinpoint the cause; timely repairs save fuel and prevent larger, costlier failures later.
• Nalley Toyota of Roswell typically costs less than independent shops while delivering higher-level service and genuine parts.
• Remember: repairs covered by warranty must be done at a certified dealership to maintain coverage.

How much does a check engine light diagnostic cost for a 2025 Toyota Highlander?

• Diagnostic fees vary; a scan at Nalley Toyota of Roswell pinpoints codes quickly and often identifies low-cost fixes first.
• We emphasize immediate and long-term savings — accurate dealer diagnostics can avoid unnecessary parts replacement common at independents.
• When warranty repairs are required, they must be performed at a certified dealership to remain covered.
• Ask about service specials and bundled inspections to reduce out‑of‑pocket expense while ensuring OEM procedures are followed.
• Schedule online or visit our Service Specials page to learn today bout current offers.

How long does a check engine light service take?

• Basic diagnostic scans typically take 30–60 minutes; follow-up repairs vary by issue and parts availability.
• Minor fixes like tightening a gas cap or replacing a sensor can be completed the same day.
• More complex repairs (ignition or catalytic system) may require additional time or parts — we provide clear time estimates up front.
• Using Nalley Toyota of Roswell often reduces total downtime and future costs because factory-trained technicians perform accurate repairs the first time.
• If warranted repairs are needed, they must be completed at a certified dealership to preserve coverage.